The present invention relates to pipe couplings. The invention is particularly useful in a universal-type pipe coupling adapted to receive a wide range of pipe sizes and materials. The invention is therefore described below particularly as applied to the universal-type pipe coupling, but it will be appreciated that the invention could also be used in other applications.
Pipe couplings in general must receive a precise predetermined length of the pipe and must securely hold the pipe against large pull-out forces. In addition, where the pipes are used for conducting liquids or gasses particularly at high pressures, the pipe coupling must also assure a good seal to prevent leakage. For these reasons, pipe couplings are generally constructed in a wide range of sizes and of different designs to accommodate pipes of different diameters and materials.
Various constructions of universal-type pipe couplings have been developed to enable the pipe coupling to accommodate a wide range of pipe sizes. Examples of the presently-known couplings of this type are described in patent application PCT/GB93/02630, published Jul. 7, 1994, and in U.S. Pat. No. 3,986,737, issued Oct. 19, 1976.
An object of the present invention is to provide a pipe coupling having a number of advantages making it especially useful as a universal-type pipe coupling, as will be described more particularly below.
The present invention relates particularly to the type of pipe coupling comprising a housing including a first section formed with a bore for receiving a pipe to be coupled, and a second section attachable to the first section and movable axially thereof to fix the pipe within the bore; and an elastic split ring received within the second section for enclosing the pipe to be coupled, the split ring having an outer conical face engageable with an inner conical face of the second section and effective, upon moving the second section axially to fix the pipe within the bore, to compress the split ring such as to decrease its internal diameter and thereby to cause the split ring to firmly clamp an enclosed pipe.
According to one aspect of the present invention, there is provided a pipe coupling, comprising: a housing including a first section formed with a bore for receiving a pipe to be coupled, and a second section attachable to the first section and movable axially thereof to fix the pipe within the bore; the second section of the housing being a nut formed with a bore for receiving the pipe to be coupled; the nut being a unitary member formed at one end with threads for attachment to the first section, and being reduced in diameter at its opposite end to define an inner conical face; and an elastic split ring received within the nut for enclosing the pipe to be coupled, the split ring having an outer conical face engageable with the inner conical face of the nut and effective, upon moving the nut axially to fix the pipe within the bore, to compress the split ring such as to decrease its internal diameter and thereby to cause the split ring to firmly clamp an enclosed pipe; the opposite ends of the split ring defining the split thereof being laterally offset from each other, in the unstressed condition of the split ring and having flat inner and outer faces, such as to permit the split ring to be compressed to substantially decrease its internal diameter, by the offset ends moving in overlapping relation to each other, thereby enabling the split ring to clamp pipes having a wide range of outer diameters.
According to further features in the described preferred embodiment, the first section is a a body member formed with the bore for receiving the pipe to be coupled; and the split ring is of a plastic material and formed with a plurality of axially-extending, cicumferentially-spaced ribs having outer tapered surfaces definning the outer conical face.
It will thus be seen that such a construction assures that the pipe coupling will grip the pipe for substantially the complete 360xc2x0 circumference of the pipe, irrespective of the pipe diameter. This construction therefore permits the pipe coupling to be manufactured according to a standard size, or a relatively small number of standard sizes, each standard size being able to accommodate a large number of pipe diameters. Such a feature relieves the user from the necessity of stocking a large number of parts for different pipe diameter sizes, and substantially reduces the costs of initial tooling, production, maintenance and repair.
According to another aspect of the present invention there is provided a pipe coupling, comprising a housing including a first section formed with a bore for receiving a pipe to be coupled, and a second section attachable to first section and movable axially thereof to fix the pipe within the bore; and an elastic split ring received within the second section for enclosing the pipe to be coupled, the split ring being formed with a plurality of axially-extending, circumferentially-spaced ribs having outer tapered surfaces defining an outer coni al face engageable with an inner conical face of the second section and effective, upon moving the second section axially to fix the pipe within the bore, to compress the split ring such as to decrease its internal diameter and thereby to cause the split ring to firmly clamp an enclosed pipe; the split ring including a plurality of hard teeth fixed within at least some of the axiallly-extending, circumferentially-spaced fibs and projecting radially inwardly past in inner face of the split ring, at circumferential spaced locations thereof, which teeth become embedded in the outer face of a pipe when enclosed and clamped by the split ring.